Contour-milling method and means



March 19, 1957 H. WALTI 2,735,503.

CONTOUR-MILLING METHOD AND MEANS Filed Feb. 14, 1952 s Sheets-Sheet 1March 19, 1957 H. WALTI CONTOUR-MILLING METHOD AND MEANS 6 Sheets-Sheet2 Filed Feb. 14. 1952 March 19, 1957 Filed Feb. 14, 1952 H. WALT]CONTOUR-MILLING METHOD AND MEANS 6 Sheets-Sheet 3 March 19, 1957 WALT]2,785,608

CONTOUR-MILLING METHOD AND MEANS Filed Feb. 14, 1952 6 Sheets-Sheet 4March 19, 1957 H. WALT! CONTOUR-MILLING METHOD AND MEANS 6 Sheets-Sheet6 Filed Feb. 14, 1952 United States Patent CONTOUR-MILLING METHOD ANDMEANS Hans Walti, Zurich, Switzerland, assignor to Ardag, Ap-

plied Research and Development, Zurich, Switzerland, a Swiss company 2Application February 14, 1952, Serial No. 271,514 9 Claims. (Cl.90-13:.4)

Master forms having irregular surfaces, such as are used in profilingthus far have been filed by hand .down to the desired final dimensionsaccording to workshop drawings. Such operation is very time-consumingand costly. The present invention discloses a new way for machining suchmaster forms.

The method disclosed in my present invention is characterised in thatfirst a net of any desired fineness is produced on the rough orsemi-finished work, such net comprising for example milled longitudinaland transverse grooves of which the bottom corresponds to the desiredfinal dimension, whereupon the remanent material is removed at leastuntil the desired final dimension has been reached, i. e. until the saidgrooves have disappeared. In a modification of such method, the materialis removed down to a level which is below the said dimension, so thatthe said net projects in raised form from the remanent surface,whereupon the latter is brought up to the said dimension by depositing afilling material.

The means for carrying out such method disclosed herein, compriseselements for gripping the work, and a cutting tool within the range ofthe latter, the said elements and work and tool beingvariablebothaxially and at rightangles thereto. The essence of the invention isdefined by operatively connecting the setting or adjusting elements to atracer which is, adapted to be moved along patterns which are reproduceable in two dimensions, the

relative movement between work and tool being defined by the relativeposition of feeler and pattern.

Various forms of the means disclosed bymy present invention are shown inthe accompanying drawings, in which- Fig. l shows a perspective view ofa semi-finished work,

Fig. 2 illustrates one form in a perspective view of the means formachining a work at right angles to its 1on gitudinal axis,

Fig. 3 shows the same means in plan view,

Fig. 4 shows the means for machiningthe work along its longitudinalaxis, r r

.Fig. 5 depicts a modification of Fig. 4, Fig. 6 shows a modification ofthe means for diesinking, y j y Fig. 7 is a perspective view, in alarger scale, of :a die,

Figs. 8-10 show another form of the invention, and,

Fig. 11 is a modification of such last form.

For explaining the method and subsequently the means for carrying thesame into effect, thepreparation of a compressor-blade masterform willbe described by way of example. Theparticular compressor blades may be;

made by profiling for which purpose a profiler is used which iscontrolled by tracing a three-dimensional master form. Up to thepresent, the latter has been made by manual filing on the basis of theworkshop drawing,

which is very time-consuming and costly.

According to the method disclosed herein, a net is produced on the work,e. g. by milling a plurality of grooves or by drilling a plurality ofbores of which the bottom corresponds to the final dimension of themaster 2,785,608 Patented Mar. 19, 1957' ice form. Such net in theexample shown comprises grooves 2 and 3 which subdivide the entiresurface of the work 1 into zones 4. Having produced these grooves, thematerialis removed until the final dimensions are reached, the groovebottom serving as profiling face whereby it is no longer necessary tocontinuously check the dimensions of the work. The material thus isremoved down to the level of the groove bottoms, so that the groovesdisappear.

A further possibility consists in removing so much material from thezones that the net projects from the remanent surface in the manner of arelief, i. e. the initial grooves are converted to ribs. The surfacesubsequently is completed to the final blade dimension by applying afilling material up to the level of said ribs.

The net suitably is so arranged that the grooves are substantiallyparallel or at right angles to the longitudinal gravity axis of theblade. To produce the net, sectional drawings first are made of themaster form, the sections being taken along the grooves to be produced.These drawings serve as pattern for producing the net, in a manner to bedescribed later on.

A means for such purpose is shown in a perspective view in Fig. 2. Theoperating table 5 comprises two conventional centers 6 which are axiallymovable and mounted in bearings 6', and serve to receive the work 1which is to be machined. The latter suitably is so secured and centeredthat its longitudinal axis is coaxial to the longitudinal axis of thecenters 6. The arrangement is, such that the work 1 is rotatably engagedthrough rotation of the work spindle by means of a driver and center 6.The machining tool, e. g. a milling cutter, is designated by 8 and isdriven by an electric motor 7 for which purpose the cutter is connectedto the motor shaft inknown manner. The electric motor 7 is mounted on across-slide 9 which is movable at right angles to the axial direction ofthe work. Such movement is carried out by means of a handwheel 10 in thedirections indicated by the arrows P1, the structural details of suchmoving mechanism not being shown in detail. Such: mechanism maycomprise, in conventional combination, a spindle connected to thehandwheel and a spindle nut -connected to the slide 9. The latter isconnected to one endof a flexible tape 11 of which the other end isWound on a roller 12. Thelatter is fixed to a shaft 13 which extends inparallel relation to the longitudinal axis of the clamped work and whichat its other end supports a second roller 14, an intermediate shaftbearing beingdiscross-sectional drawing 20. The latter is exchangeablymounted on the wheel 20 and represents a cross-section through themaster form in accordance with which a groove of the said net is to bemachined. The tool 8. also is longitudinally adjustable with respect tothe work; and is set at that position which corresponds to. the mountedcross-section. In order to keep the tapes 11 and 16 always taut, aweight21 is suspended from the roller When moving the tracer 18 along thecontour ofthe cross-section 20, which is done by simultaneously actuat-Ting the handwheel 10 and a handwheel. 22 for'rotating the work 1together with the Wheel 19 around the longih tudinal axis, whereby themilling cutter or tool is rotated,[ a groove is milled in the workcorresponding to the con;

tour of the cross-sectional drawing. In place of the manual operation, apush-button control could be provided Similarly, othercross-sectionaldrawings are sue-- cessively mounted on the wheel 19, with the aid ofwhich other grooves are milled until all the grooves of the net havebeen produced, which grooves run parallel to a transverse work plane.

In'order to dispense with full-size drawings and'attain' reduced errorsthrough reducing the scales, the'diameters' of the discs 12 and 14 areso chosen that the movement's of tracer- 18 are transmitted to the toolmovements in accordance with the scale of the drawing.

The longitudinal grooves 3 (Fig. l) are milled with the aid oflongitudinal-section drawings. The work 1 is again clamped betweencenters 22- which are disposed on the w'orkbench 23 (Fig. 4). The latteris movable by actuating a-handwheel 24 inthe directions of arrows P2.Such movement is transferred on to a spline shaft 27 by means of a tape25 and pulley 26. The spline shaft 27 carries a' roller 28 on which i'swound a tape 29 which is connected to asupport 30 of a tracer 31. Aweight 32 tendsto turn the shaft 27 so as to keep the tapes 25 and 29always taut. By means of the arrangement'describcd, the r'eciprocatorymovements of workbench 23 aretransferr'edonto the tracer 31, any desiredgear ratio being attainable between the movement of the workbench andthe tracer through a suitable choice of the relation of diameters of thetwo discs 26 and 28. The support 30 and tracer 31 are mounted on a slide33 which is movable at right angles to the direction of movement of theworkbench in direction of the arrows P3, the slide 33 being providedwith a driver 34 which transmits the slide movements indirection of thearrows P3 to the disc 28 which is movable but non-rotatable on thespline shaft 27.

The slide 33 is so coupled to a tool carriage 35 which carries anelectric motor 36 and cutter 37, that the movements of carriage 35 aretransmitted to the slide 33 at right angles to the longitudinal axis .ofthe work. The carriage 35 is moved in said direction by means of ahandwheel 38. The slide 33 and the carriage 35 may be interconnected,for example, by means of a tape-transmission 39 to 41, or the twomembers 33 and 35 may be integral. Within the-range of the tracer isarranged a work table 42 which serves to receive longitudinal-sectiondrawings 43. V

The mode of operation'of the automatic profiling-ma chine portiondescribed is as follows.

On the worktable 42' is tacked down a longitudinalsection drawing 43 ofthe'master form according to which a-- groove 3 is to be milled. Thework 1 is so set with respect to'the cutter 37 that the horizontal planepassing through the work coincides with the cutting plane of the"drawing. Through simultaneous actuation of the hand wheels 24 and 38, orthrough an automatic push-button control, the tracers are caused toaccurately follow the longitudinal edge of the drawing. The cutter 37'under goes a corresponding movement so that the work 1 is machined inaccordance with the drawing. By using" various sectional drawingsrepresenting longitudinal sections laid through different axial planes,the longitudinal work grooves 3 are produced. 7

Afterhaving milled the net shown in Fig. 1 in the work, somuch materialis removed from the zones 4' (Fig. 1")' between the'gr'ooves until thefinal dimensions have been reached or just passed or understepped. cascth'e said zones are filled with a plastic material up to the finaldimensions.

A modification of the means shown in Fig; 4' illustrated in Fig. 5. Herethe work 1 again' is clamped between o ce 44 ich a dispos d .1 a slide 4h atter' h ugh a t io o a; h ndwheel. 46 is mo able in i' etji nof h aro P4, nd su h movem nt i ans i cd ough t smis'sion 7 0 4 to orktable 50hich. se e e o s udinahs c' i ndr win 51 To trace thelatter, againatracer- 52-is'providedto which is coupled the cutter 54 which isoperated by an In the latter electric motor 55. The movement istransmitted by means of steel tapes 57 and 59 via pulleys 57* and 59,the pulley diameters being, in the same relationship as the master formand the drawing.

By simultaneously actuating the two handwheels 46 and 53, the tracer 52and table 50 are so moved relatively to each other that the" movementtakes place in accordance with the longitudinal contour of the sectionaldrawing 51 and is transmitted onto the tool 54 and work 1. l a a In 6and 7 is shown a die-sinking form ofinvention. The article 60 to bemachined is clamped between the centers 61 and 62 of a workbench 63. Inthis case also, a milling cutter 65 is driven by an electric motor 64which together with the cutter is mounted on a crossslide 66 which bymeans of a handwheel 67 is movable in direction of the arrows B at rightangles to the axial direction of the work. The reciprocatory movement ofcross-slide 66 is transferred on to a tracer 72'thro'ugh a rigid gearing68 40 and a flexible tape 71, the latter being'windable' and unwindableon to and from a 'drum' 73. The arrangement is such that the drum 73 isoperatively connected to the last link 70 of said gearing. The

tracer 72 is disposed in the range of a wheel 74 which is secured to theshaft of center 61 and which serves to receive a cross-sectional drawing75. The latter is exchangeable on wheel 74 and shows a cross-sectionthrough the master form according to which a groove of the netis" to bemilled. The tool 65 with respect to the work also is adjustable in thelongitudinal direction and is so ad'- justed that the selectedposition'corre'sponds to the crosss'ec'tion shown in the drawing 75.When the tracer 62 moved along the contour of the drawing75, which maybe done through actuating the handwheel 67 and a further handwheel 76,and when the cutter 65 is rotated, a groove is milled in the work 60.The longitudinal grooves are produced through the use of correspondinglongitudinalsection drawings. In order to make the electric motormovable along the work 60, the cross-slide 6 6 may be mounted in similarmanner as shown in' Fig. 2.

A last form of invention is shown in Figs. 8-10. Also in this case, awork 87 shall be machined which is to serve as a master form. Themachining means comprises a frame 81, Fig. 9, which is provided with avertical guide 130 in which a rise-and-fall rest 83 is mounted. Theadjustment is known per se and may for' example be accomplished by meansof a spindle gearing. A slide 131 is mounted movable in direction'of thearrows 84,

84' on the rest 83. For such purpose, a guide track 8'2",

131'i's' moved longitudinally in it's guide track82', 82".

by'meansof a spindle (not shown) which is actu'ab'le by means of ahandwheel 106 which is connected to an 93 which: also is mounted in theslide 131an'd carries a '75 articulated shaft. The latter, as best shownin Fig.' 10, comprises a telescoping portion 111 and an articulated:portion 110 which is operatively connected to an angle gearing. Thelatter comprises two bevel gear wheels. of

which the axes stand at right angles to each other, the

wheel 108 being actuable by means of a handwheel1'06".

Inthis manner it is possible to move the slide 131 through the handwheel106" as well as through the handwheel 106". The telescoping'portion 111is not further detailed in the drawing and may conventionally comprisetwo.

telesc'opable sleeves or sliding bushes.

The slide 131 comprises a clamping device 86in which thew'ork. 87'i's'received. At the other end a conventional center 86" is provided, whichis securedin an arm 131 of slide 131. Within the range of wbrkS-Zacutter 88 is secured t o arotatable shaft The cutter 88 is driven by"means of an electric motor 90, Fig. 8, through a belt 9 in. a-ma n rknown per s The clamping means 86 is rigidly connected toa shaft worm 94at its-end remote from the tool. The Worth 94 Qmt asses coacts with aworm wheel 95 which is secured to a shaft 95' standing at'right anglesto shaft93. The other end of shaft 95' is connected to an articulatedshaft 96 which is coupled to' a telescoping element 97. The latter isformed similar to the element 111 and transmits the rotation of wormwheel 95 on to a worm 98, Figs. 9 and 10, which is mounted in extreme134 and engaged to a worm wheel 99 which serves jto drive a turntable100. The cross-sectional drawing of the work to be machined, whichdrawing may have any desired scale, is tacked down on the table 100andis traced by means of a tracer 120. The shaft 101 of worm 98 isactuated through a handwheel 103. ZBy-actuatingthe latter,'the turntable100 and the work 87 are synchronously rotated. Another possibilitywouldconsist in driving the table 100 and the work 87 coupledtheretothrough an electric motor via an infinitely variable gearing.

An articulated mechanism is provided for transmitting the movement ofslide 131, which movement is brought about through the actuation of thehandwheel 106' or 106", on to the .tracer1120sl Such articulatedmechanism comprises the following parts. On the horizontally movableslide or milling table 131 are provided two holders 127, Fig. 9,formounting a vertical shaft 126 on which dne end of a connecting rod123, Fig. 10, is rotatably mounted. The latter is rotatably mounted in aslide way andxmovably secured to the column 81. The spindle carrier131'only performs the feedmotion at right angles to the direction ofmovement of the carriage 83. The other end of rod 123 is provided with aslide bush 123 and is connectedto arod 1 2 1 at 123 .g' Therod 121isguided through the two fixed bearings 122, a cross way 124 beingprovided between the two bearings. The said cross way is rigidly securedto the rod 121 and forms,

so to speak, a portion of the latter, the cross way comprising a bore136 which extends at right angles to the rod 121 for receiving a rodlikecarrier 118. The latter is guided axially movable in said bore 136. Atone end of the carrier which extends to the turntable 100, the tracer120 is secured, whilst the other end of carrier 118 carries a socket 137which is slidably mounted on a tie rod 116. The latter is disposedbetween two rods 115 which extend parallel to each other and parallel tothe carrier 118, and at their other ends are slidably mounted inbearings 114. The latter suitably are fixed to the standard 134. Anothertie rod 117 is disposed parallel to the rod 116 which is connected tothe two rods 115. The tie rod 117 carries one end of a rod 138 which atits other end is pivoted to a slide member 141. The latter is formed asspindle nut and coacts with a spindle 140 which is mounted in bracket139 and carries a handwheel 142. The latter serves to the lever ratiothrough shifting the slide member 141. An electric motor 144 serves toautomatically feed the cutter tool.

The arrangement described again allows of moving the tracer 120 alongthe contour of a drawing 146, such movement being transformed to arelative movement between the work and the cutter. Tracing the contouron drawing 146 may be done according to polar or Cartesian coordinates.In the former case, the turntable 100 is rotated by actuating thehandwheel 103, which rotary movement is transmitted in the mannerdescribed via the articulated transmission on to the shaft 93 of thechuck 86 so as to cause a corresponding rotation of the work.Furthermore, the tracer 120 is moved axially with respect to the rodlikecarrier 118, brought about by actuating the feed mechanism. When thespindle carrier 135 is fed in direction of the arrow P, which may bedone either automatically through the electric motor 144 or by actuatinga handwheel (not shown), such feed is transmitted through the rod 138which is swiveled about its point of connection to the handwheel 142.Such swiveling motion of the guide rod gives origin to an axial movementof the rods 115, and the latter movement in turn gives origin to thesaid axial movement of the tracer 120. In order to allow of varying theratio of feed to the movement of the rods 115, the said spindlearrangement 140, 141 is provided, the effective length of rod 138 beingvariable through actuation of the handwheel 142.

When the masterform drawing is to be traced according to the system ofCartesian co-ordinates, the tracer 120 is given two movements at rightangles to each other. One of said two movements released by the feed ofthe spindle carrier 135, whilst the other movement is brought about byactuation of the handwheel 106 or 106". By rotating the said handwheel,the carriage 83 is moved in the ways 32 and 82", which movement istransmitted on to the rod 123 which is connected to the carriage 83. Bymoving the latter, the rod 123 is swung to the position shown bydash-and-dot lines in Fig. 10, and the rod 121, which is connected tothe rod 123, is axially moved. Since the rod 121 is rigidly connected tothe cross-guide 119, the latter and the carrier 118(whicl1 is mountedaxially movable in said guide) follow such swing; one end of saidcarrier moving on the tie rod116. A movement at right angles to theaxial direction of carrier 118 thus is imparted to the tracer 120.

The machine of Figs. 8-10 may be employed for cutting both thelongitudinal and the transverse grooves. To cut the longitudinal groovesit is merely necessary to turn the workpiece 87 through an angle of 90and to secure it in this position by means of the chuck or clampingdevice 86.

Fig. 11 shows a simplified modification of, the form of invention shownin Figs. 8-1(]. The parallel guiding arrangement 115, 116is-replaced bya lever construction. One end of the rod 138.is pivoted at 150 to therodlike carrier 118 of tracer 120. The carrier 118 is guided in a sleeve151 and at one end at 152, is pivoted to the support 153. The rod 121 ispivoted to said sleeve 151, the fulcrum being designated by 154.

A movement in direction of the arrows B is transmitted through theconnection 123 and 121 on to the sleeve 151 which thereby is swung aboutthe fulcrum 154. The tracer is deflected in accordance with thetransmission ratio defined by the ratio of the lengths a to b. Amovement in direction of the arrows C is transmitted through the rod 138and the carrier 118, as has been described above with the aid of theform of invention shown in Figs. 8-10. In the modification shown in Fig.11, the rod 138 at one end is pivoted to a slide 141 which is movable byrotating a thread spindle 140. The rod 138 further is guided in a sleeve138 which in turn is pivoted at 143. By moving the slide 141, thetransmission ratio is variable with which the movements are transmittedon to the carrier in direction of the arrows C.

I claim:

1. A profiling machine, comprising a cutter having horizontal feed, avertical movable carriage having a work-carrier horizontally movable atright angles to the feed movement, a first articulated connectionbetween the work-carrier and the tracer and adapted to transmit thehorizontal work-carrier movement on to the tracer, a second articulatedconnection between the work carrier and the tracer to transmit thework-carrier feed on the tracer, a third connection arranged between thework carrier and a turntable, which turntable carries a twodimensionalpattern, said third connection transmitting the rotary movement of thework-carrier on to said turntable. i

2. A profiling machine according toclaim 1, having a first articulatedconnection comprising a lever transmission which has a pivotable leverand a connecting rod, said lever being pivoted to a horizontal rod andadjustable in elevation and connected to the work-carrier, the other endof said lever coupled to the rod end, which rod is provided with acrossway and guided in fixed guides.

3. A profiling machine according to claim 2, having a tracer-carryingslide, guided by the crossway axially movable at right angles to therod.

4. A profiling machine according to claim 3, having a.

are-man s cond arficulateieanae fi.naemmisin; a .c l tefl QlWQ 'QP E "ah ee dfid th tam an a the .Qthe end to an adapter and at a ppintintermediate cf the vejldsto al.-further guide,twoparallel guidesextending at righttangles to the-.adapter and rigidly connected to saidadapter and to aconnecting element, extending parallel to the adapter, said guides being mountedat one end in sl a a c nne t n e eing wnn cte iaxially movable manner v to the carrier-end, which is remote from thetracer, .the swinging movement (pf said articulatedlever, initiated,by-said further guide causing the Y axial movement of said parallelguides.

-5. ,A profiling machine.. accordi ng to claim .4, having ae d d oiie e.-.s ,su d vm be n tc nnecte o a s i hiq fiqaqtswit p n l m untedsqnahead. I

6- ;A qfi i g m in acc din t cl m 5 h vin a th r co ect sa d zsonnq tiesompr s n a .-.t epa e e a -an ar icu ed, sha .cQ p e t th latter; [saidmember being connected toa turntable-carry: ing'a drawing'pattern bymeans of a worm wheel and worm, said articulated shaft being alsocoupled-to the cutter carrier shaft byworm and worm wheel means.

7. A profiling machine comprising a work carrier, a cutter disposedinthe range of the worlg; means f or setting said cutter and work carrierwith respectto each other both horizontally and vertically, meansoperatively connecting said workcarrier to a tracer which is adapted tobe guided along-two-dimensionally reproducible pab terns, therelativemovementvbetween work.-and cutter being defined by the relativeposition between tracer two-arm lever, .which;comprises ;tw0 mods which:are

guided in a sleeve, one ofqsaidirodsabeing:mountedrina slide, saidsleeve hein xonneeted pivotably :but :axially nonmovably to ;..t hework-c rrier. -or .the .espindle :hetid tespe t v ya a ;9. l Aprofiling; machine {according ,to. c1aim':-7,:;having -a lev tranmission co pris g arswins lever n 9 necting rod, the swing leverbeingconnected to-the work carrier.

References .Cited .in the lie of =this;patent [UNITED 'STATES PATENTS Iv2,151,743) Chladek ;Mar. 28, 1939 2, 17 .8,4.41 Swanson ..1 Oct. -3 1,.1939 2,239,227 :Morton g t Apr. 29, 1941 2,369,043 Halford Feb. 6,1945' 2;-3 83 ,1-65 Schuyler ;Aug. 21, 1945 .-2,388',555 i :Kuehni :etal. ...;Nov. 6, 1 945 2,424,031 H July -1s, 1947 2,6757310 Campbell'-May 4, 1954

